Experimental study of an air-breathing pulse detonation engine ejector

Experimental studies were performed in order to improve the understanding of the performance of ejector driven by an air-breathing pulse detonation engine (PDE) with a convergent nozzle. This research utilized a gasoline-air PDE at four different operating frequencies of 8 Hz, 10 Hz, 12 Hz and 15 Hz. The performance of PDE-ejector was quantified by thrust measurements. The effects of single ejector length and axial location on thrust augmentation were investigated. It was found that the single ejector with L/D of 2 showed the best performance and the maximum thrust augmentation occurred at a downstream placement of +1 tube diameter. The performances of two-stage and three-stage ejectors were also investigated. The results indicated that both the overlap ratio and the flow area between two stages should not be too large. The performance of the two-stage ejector was not as sensitive as single-stage ejector to axial position in current conditions. The three-stage ejector behaved better than the two-stage ejector but worse than the single-stage ejector in this work. A maximum thrust augmentation of 1.8 was obtained with an L/D of 2 at a downstream placement of +1 position and 15 Hz operating frequency.